Variable reverse pitch fan for cooling systems



Nov. 5, 1957 A. E. SWAN 2,812,027

VARIABLE REVERSE PITCH FAN FOR COOLING SYSTEMS Filed June 23, 1955 s Sheets-Sheet 1 7 .fildon 1: 51106211 INVENTOR I BY 7 I I v ATTORNEYS Nov. 5, 1957 A. E. SWAN 2,812,027

VARIABLE REVERSE PITCH FAN FOR COOLING SYSTEMS Filed June 23, 1955 5 Sheets-Sheet 2 INVENTOR BY W.

ATTORNEYS NOV. 5, 1957 SWAN 2,812,027

I VARIABLE REVERSE PITCH FAN FOR COOLING SYSTEMS Filed June 23, 1955 3 Sheets-Sheet 3 flldon E. Swan INVENTOR 3531/ 6. 3 5 a.

ATTORNEYS United States Patent 2,812,021 VARIABLE REVERSE PIICHU FAN FOR COOLING SYSTEMS Aldon E. Swan, Westwood, Calif.

Application June 23, 1955, Serial No. 517,518

1 Claim. (Cl. 170160.43)

This invention relates to fan construction, and more particularly to the construction of fans used in supplying the air delivered to the radiators of heavy duty earth moving machinery, to maintain the engine of the machine cool.

An important object of the invention is to provide a fan mounted at the rear of the radiator of the machine for drawing air through the radiator coils of the cooling system of the machine, means being provided for reversing the pitch of the fan blades to cause the air to move in the opposite direction to clear the radiator of an accumulation of dust or foreign matter which may collect on the radiator coils during the normal operation of the machine, to improve the efficiency of the cooling system of the machine.

Another object of the invention is to provide means for regulating the volume of air produced by the fan to meet various weather and starting conditions, to insure the maximum efficiency of the engine.

Still another object of the invention is to provide a device for regulating and adjusting the pitch of the blades of a cooling fan of an internal combustion engine from a point adjacent to the oper-ators seat, or from a point remote from the engine.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings,

Figure 1 is a side elevational view of a fan constructed in accordance with the invention.

Figure 2 is a front elevational view thereof.

Figure 3 is a plan view thereof.

Figure 4 is an enlarged longitudinal sectional view through the hub of the fan.

Figure 5 is a transverse sectional view taken at right angles to Figure 4.

Figure 6 is a sectional view taken on line 6--6 of Figure 1 of the drawings.

Figure 7 is a plan view of one of the shoes used in providing the connection between the crank arms of the fan shafts and adjusting collar of the fan.

Figure 8 is a longitudinal sectional view through the hub of the fan illustrating the fan blade operating means moved to adjust the pitch of the blades of the fan.

Referring to the drawings in detail, the fan forming the subject matter of the present invention, comprises a hollow hub 5 which is provided with integral pulleys 6 over which the usual fan belt 7 operates. The reference character 8 indicates a bearing that is fitted in one end of the hub, while at the opposite end of the hub is another bearing 9 also secured within the hub. These bearings 8 and 9 are equipped with bearing races 10 in which the hollow shaft 11 operates. One end of the hub is closed 2,812,027 Patented Nov. 5, 1957 by thecap If. which also forms a stop for the seal fiiig IS c'arriedLby; end of we 1i. a l I The hub 5 is provided" with openings" in which the operate, the shafts 1 4 supp oriing' the fan blades 151 that; are connected. thereto and disposed Ibn ittainally'of the shafts 14, the blades 15 operating exteriorl-y th r r r The inner ends ofthe shafts14 are secured to the crank arms 16, which crank arms have tapered pins 17, which pins are adapted to be positioned in one of the openings 18 of the shoe 19 associated therewith, there being two of such shoes provided in the unit, each shoe having a plurality of openings 18 for adjusting the throw of the crank arms 16.

These shoes are so constructed that they fit over the periphery of the sliding collar 20 which is formed with a bearing 21 provided with a bearing race 22 that fits on the adjusting sleeve 23 that, in turn, is slidably mounted over said hollow shaft 11. The hollow shaft 11 is formed with slots 24 formed longitudinally thereof, and through which the pin 25 extends, which pin connects with the sleeve 23 at its ends.

The operating rod 26 extends into the hollow shaft 11 and connects with the pin 25 intermediate the ends thereof, the operating rod passing through the bearing 27 secured in one end of the shaft 11, as better shown by Figure 6 of the drawings.

The control end of the rod 26 is located on the instrument board of the machine so that the operator of the machine will have ready access thereto to operate the blades to cause them to take various angular positions with respect to the side wall of the hub of the fan, adapting the fan for a particular use.

The reference character 27 indicates a bracket arm by means of which the fan is supported with respect to the radiator through which the air is passed.

While I have described the invention as adaptable for use in connection with the fans forming a part of the cooling system of internal combustion engines, it is to be understood that it is within the scope of the invention to incorporate the principles of the present invention, in fans used in air conditioning units.

From the foregoing it will be seen that due to the construction shown and described, I have provided a fan to be used as a part of a cooling system, wherein the blades may be tilted to various angles to regulate the output of the fan.

In operation, it is only necessary to manipulate the op erating rod 26 to move the sliding collar 20 longitudinally of the shaft 11, which causes a movement of the arms 16 which, in turn, transmit rotary movement to the shafts 14 on which the fan blades 15 are mounted, to vary the pitch of the blades.

It will be obvious that as the blades are moved to an open position, the air velocity will be increased, and when it is desired to reduce the volume of air, the fan blades are moved to more of a closed position, as desired, to reduce the output of the fan.

It will also be seen that due to the construction of the fan, it is possible to rotate the fan in one direction to draw air through the radiator of the cooling system of an internal combustion engine for cooling purposes, and then to reverse the pitch of the blades so that the air will be forced through the coils of the radiator in the opposite direction, removing all foreign matter which may collect on the coils of the radiator and which has a tendency to coat and insulate the coils of the heating unit.

I claim:

A reversible and variable pitch fan comprising a hollow hub having a pair of opposed openings, two fan blade shafts, one rotatable in each opening, a fan blade on each fan blade shaft, a tubular shaft in said hub perpendicular to said fan blade shafts, anti-friction bearings at each end of said hub engagingabout said shaft, said tubular shaft having opposed elongated openings, a sleeve adjusting rod loosely disposed in said tubular shaft and projecting from one end thereof, a right-angularly disposed pin fixed on the inner end of said rod, said pin loosely extending through said elongated openings and fixed to said sleeve, a collar loose on said sleeve, a crank arm fixed on the inner end of each fan blade shaft, a pair of diametrically opposed U-shaped shoes engaging 4 the periphery of said collar, and a pin connecting a crank arm with a shoe, each shoe having a plurality of openings in a selected one of which said latter named pin is engageable whereby to vary the maximum and minimum adjustment of said blades.

References Cited in the file of this patent UNITED STATES PATENTS Murray July 12, 1921 Ehinger July 12, 1927 

